This invention relates to novel emitting materials for organic electroluminescence (EL) devices. As a promising technology for flat panel display, organic EL has attracted more and more attentions. The early efficient devices have been reported in C. W. Tang, S. A. Van Slyke, Appl. Phys. Lett. 1987, 51:913xcx9c915 and U.S. Pat. No. 4,720,432 issued Jan. 19, 1988. Great improvements have been made since 1987 and many new materials have been synthesized and used in organic EL devices. There are diverse emitting materials used in fabrication of organic EL devices with blue, green, yellow, and red emission.
The primary object of this invention is provide to a series of stable complexes based on many kinds of tridentate ligands. These materials exhibited strong fluorescence and excellent amorphous properties in solid state. Both of these characters are conducive to forming high quality amorphous films.
Another object of the invention is provide to the use of such novel complexes as thermal stable emitting materials for organic light-emitting diodes (OLEDs).
This invention disclosed here a series of stable complexes which have a tridentate ligand. Almost all of these complexes have the high Tg more than 200xc2x0 C. The advantage of these materials lies in their excellent thermal stability and good performance to form amorphous films. The materials in this invention have made some progress in improving the compatibility with other layers materials. These materials have some unique characteristics that will be conducive to forming high quality amorphous films. Such novel complexes can be used as a thermal stable emitting material for OLEDs. In addition, a series of emitting colors have bene obtained from these materials including green, yellow, and red, some of which are remain rare now. And the color position in the color coordinates system shows strong potential as a red light-emitting material for organic electroluminescence. These materials can be used as emitting materials or electronic transport materials in organic EL devices.